This research project is concerned with the immunochemical study of lens proteins in normal and pathological states. The investigations of normal lens proteins involve the subunit structure of alpha crystallin. Immunochemical probes will be used for the determination of molecular changes of SH-containing or SH-free subunits of alpha crystallin e.g. with age. Such studies will be extended to also include other lens crystallins. Investigations of complex formation resulting from lens protein-protein interaction and its dependence on age is an additional objective. Further immunochemical studies involve evolutionary development at the molecular level. These studies are based on the direct conclusion from the evolutionary theory that common antigens in the lens of different modern species must have been derived from their common ancestor. The aim of this research is to analyze the structural alterations of individual lens proteins following evolutionary changes. The immunochemical study of the normal lens will include in addition, investigation of the antigenic composition of lens epithelial cell membranes as well as the lens capsule. The organ specific properties of the lens proteins make them uniquely suited for research on the mechanism of auto-immune responses and such investigations will be continued. Studies on the lens in pathology will have as their aims the mechanisms of lens-induced uveitis and the mechanism of cataractogenous changes. The latter immunochemical studies will be mainly concerned with changes in the molecular structure of lens proteins or changes of lens protein-protein complexes associated with cataracts and their relation to aging. The possible pathological consequences of anti-lens antibodies will be explored in vivo and in vitro.